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As the Gulf of Mexico recovers from the Deepwater Horizon oil spill, natural resource managers face the challenge of fully understanding the impacts of the spill and setting priorities for restoration work. The full value of losses resulting from the spill cannot be captured, however, without consideration of changes in ecosystem services--the benefits delivered to society through natural processes. The use of an ecosystem services approach to damage assessment is currently limited by an incomplete understanding of ecosystem interactions and the lack of data, especially on the economic and societal effects that derive from environmental changes.

Key Messages

For a spill of the magnitude of Deepwater Horizon, it can be difficult to assess injury to the ecosystem based on injuries to individual resources. An ecosystem services approach provides a more holistic view of the overall range of damages and informs options for restoration. This approach requires an understanding of several factors, including the impacts of disturbances on the structure and basic functioning of ecosystems; how changes in ecosystems affect the potential provisioning of ecosystem services; and the impacts of changes in ecosystem services on human well-being, and in monetary terms.

Conceptually, an ecosystem services approach has many advantages, but its actual application faces a number of challenges. For example, scientists need an understanding of pre-spill (or baseline) ecosystem conditions in order to judge the extent of damage caused by the spill. Depending on the ecosystem service being addressed, the amount and quality of data available varies substantially. Furthermore, many ecosystems are rapidly changing and were already degraded prior to the spill, making pre-spill baselines more difficult to establish.

Some ecosystem services can be translated to a monetary value relatively easily—for example, the role of coastal wetlands in reducing the intensity of storms can be valued by calculating the cost of repairing storm damage that would have been incurred without protection from wetlands. However, work has only just started to determine the value of other, less-studied ecosystem services.

Difficulty also comes from the lack of comprehensive ecosystem models to evaluate the full impact of events such as the Deepwater Horizon oil spill. These models would allow greater understanding of how the elements of the ecosystem interact and produce services of value to humans.

The response effort to the Deepwater Horizon oil spill involved using several remediation technologies in ways or at scales never before attempted. Incorporating more science into the remediation process would help scientists employ the most effective response technologies and determine the endpoint of the response effort. A better understanding how the response effort affected the environment will not be possible until damage assessment data and the results of long-term monitoring studies become available.

The funding that will be available through criminal and civil settlements offers an unprecedented opportunity for research to establish a better baseline understanding of the Gulf of Mexico ecosystem and further develop an ecosystem services approach to damage assessment. The Committee identified research needs that will help implement an ecosystem services approach in the Gulf of Mexico.

There is a critical need for an overarching infrastructure for organizing and integrating the wealth of data that has been and will be collected in the Gulf of Mexico. This infrastructure will be needed to support comprehensive ecosystem models that can be used to evaluate the impacts and linkages between ecosystem services.

In the long-term, more comprehensive models that can relate the drivers of change to the structure and function of the ecosystem are needed. Such a system would incorporate all the relevant processes—including biological, physical, social, and economic—to describe the dynamics of all ecosystem services in the Gulf of Mexico. In the shorter term, models of subcomponents of the ecosystem can help establish the value of ecosystem services within a distinct resource use, location, habitat, and user community.

Although a substantial body of data exists to support a better understanding of ecosystem structure and function within the Gulf of Mexico, data regarding socio-economic and human dependencies lags far behind. Collecting and synthesizing data on economic and human factors and including them in the appropriate models will help capture the full range of ecosystem impacts.

Resilience—the capacity of a system to respond to disturbances—is an important component of ecosystem management because it helps sustain a continuing flow of valuable ecosystem services. Building resilience to unpredictable events such as large oil spills will require decisions that strengthen ecosystems (for example, by promoting biodiversity) and incorporate adaptive management (the continuous integration of new data and information into management plans).